What is the explicit rule for this geometric sequence? a1=−15; an=1/5⋅an−1 an=−15(1/5)n−1 an=1/5⋅(−1/5)n−1 an=−1/5⋅15n−1 an=15(−1/5)n−1

aₙ = -15

Option A

Step-by-step explanation:

Given that,

First term      a₁ = -15

                     aₙ =

We will find the sequence

a₂ = a₁/5 = -3

a₃ = -3/5

a₄ = -3/25

Here common ratio (r) =

The explicit formula for a geometric sequence is :

aₙ = a₁

aₙ = -15

So, option A is correct!

I hope it helps you.